The sensible place to build new houses, factories and offices【主语】// is【系动词】// where people are【表语】, in cities and towns where infrastructure is in place【补充性状语】.

参考译文：修建新房子，工厂和办公室的合理的地方是在有人的地方，在基础设施都已到位的城市和城镇。

【1】The sensible place to build new houses, factories and offices【修建新房子，工厂和办公室的合理的地方】

备注： to build new houses, factories and offices为不定式短语作后置定语修饰签名名词“place”，sensible为形容词作前置定语修饰名词“place”

【2】is 【是】

【3】where people are 【在有人的地方】【where引导表语从句】

备注：where为融合性连接副词引导表语从句，并在表语从句作表语成分。where=in the place where

【4】in cities and towns where infrastructure is in place【在基础设施都已到位的城市和城镇】

备注：where infrastructure is in place为关系副词where引导的定语从句修饰前面名词“cities and towns”。关系副词where在定语从句作地点状语成分，where=in which,关系代词which指代名词“cities and towns”。

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